A typical hydroponic plant growth system comprises a nutrient base and circulates a liquid nutrient through a cultivation portion wherein the plant seeds or young plants are anchored. For example, U.S. Pat. No. 5,502,923 discloses a hydroponic plant growth system which consists of a nutrient supply module base which supplies liquid nutrient to a series of vertically stacked prop modules, each prop module containing a number of plant growth sites. As liquid nutrient is pumped to each prop module, water is distributed to the plants grown therein.
U.S. Pat. No. 4,986,027 discloses a plant growth apparatus comprising a flexible tubular element wherein slits are provided for the growth of plants. A fluid nutrient is supplied to the root permeable material via a pump system, the fluid nutrient thereby being supplied to the plants.
Similarly, U.S. Pat. Nos. 5,440,836, 5,555,676, 5,918,416 and 4,033,072 all disclose vertical growing columns for growing a number of plants which are supplied water and nutrients through the use of nutrient solution pumps in the base of the respective apparatuses, which supply liquid nutrient to the top of the apparatuses. The liquid nutrient is supplied to the plants as the liquid travels from the top of the apparatuses to the bases.
Further, the prior art indicates that multiple vertical plant grow columns may utilize a single nutrient base. For example, U.S. Pat. No. 5,363,594 discloses a structure for a vertically oriented plant growth unit having a plurality of vertical columns arranged to conserve horizontal floor space and utilize a common base for the supply of liquid nutrient.
One of the potential limitations of the growth units described above is that the various plants of the growth units may receive different types and amounts of light from whatever light source is utilized. The differences in light quality and quantity may result in a divergence in growth and quality between plants grown at various levels and on various sides of the vertical columns.
U.S. Pat. No. 6,178,692 discloses a lighting system for use with one or more vertical growing columns. The lighting system is mobile and can apparently be angled to provide for equidistant lighting to the plants at both the top and the bottom of the vertical growth column. However, it would appear that equidistant lighting is to be provided by the lighting apparatus to a single side of each growth column. Each vertical column apparently has plants growing on all sides of the vertical unit and therefore a single lighting unit would appear only to provide equidistant lighting to those plants which are somewhat facing the lighting unit. To provide equidistant lighting to all plants on the growing columns, it would appear that two lighting units are set up on either side of one or more growing columns and angled to provide top to bottom equidistant lighting on each side of the vertical grow columns, thereby providing equidistant lighting to all plants. In at least some embodiments, this system therefore appears to be limited by the requirement for multiple lighting units to create equidistant lighting to all plants.
In one aspect, the present invention provides for a plant growth unit including a plurality of growth sites, means for supporting the growth sites, and means for establishing a liquid nutrient flow. The growth sites may be radially supported about a central vertical longitudinal axis and the supporting means may define an internal space between the plurality of growth sites so that the growth sites generally face the internal space. The internal space may be adapted to accommodate a light source. The supporting means may have an upper portion and a lower portion. The means for establishing a liquid nutrient flow may circulate a liquid nutrient to the upper portion of the supporting means and past growth sites to the lower portion of the supporting means so that the liquid nutrient flow comes into contact with each of the growth sites.
In some embodiments, the plant growth unit may have two or more of the growth sites approximately equidistant from the longitudinal axis. In yet other embodiments, at least some of the growth sites are vertically spaced apart, and the growth sites at generally the same vertically level are approximately equidistant from the longitudinal axis.
In some embodiments, the supporting means may include one or more columns radially disposed about the longitudinal axis, the one or more columns having longitudinal passages through which the liquid nutrient may pass. In other embodiments, the supporting means may include one or more supporters radially disposable about the longitudinal axis, operable to form a generally closed perimeter around the internal space.
In some embodiments, the plant growth unit may further include means for containing the liquid nutrient. The containing means may be, for example, a nutrient supply module. Alternatively, the liquid nutrient may by contained within the supporting means itself.
In some embodiments where the supporting means are one or more columns, the liquid nutrient flow is established by circulating the liquid nutrient from a nutrient supply module, in fluid communication with the one or more columns, to the upper portion of the one or more columns, through a longitudinal passage in the one or more columns to the respective lower portion of the one or more columns. In embodiments where the supporting means are one or more supporters, the liquid nutrient flow is established by circulating the liquid nutrient to the upper portion of the one or more supporters past the growth sites to the respective lower portion of the one or more supporters.
In some embodiments, the plant growth unit further includes at least one pump facilitating the liquid nutrient flow. The growth sites may protrude upwardly from the supporting means and the plant growth unit may further include a plurality of baskets adapted to hold plants and attachable to the growth sites. The plants may be anchored to the growth unit by being placed inside the baskets, which are then attached to the growth sites.
In another aspect, the present invention provides a plant growth unit including a nutrient supply module, one or more columns and a plurality of growth sites supported by the one or more columns. The nutrient supply module may be designed to contain a liquid nutrient. The one or more columns may be radially disposed about a central vertical longitudinal axis to define an internal space between the one or more columns. The internal space may be adapted to accommodate a light source. Each column may have an upper portion, a lower portion and a longitudinal passage through which the liquid nutrient may pass. Further, each column may be in fluid communication with the nutrient supply module for circulation of a liquid nutrient flow from the nutrient supply module to the upper portion of each of the one or more the columns and through the longitudinal passage to the respective lower portion of each of the one or more columns. The plurality of growth sites may be radially disposed about the longitudinal axis of the growth unit, generally facing the internal space, and each growth site may be positioned to contact the liquid nutrient flow.
In some embodiments, there are at least two columns and at least one growth site on each column. Such columns may be vertically oriented. In yet other embodiments, the growth unit has at least three columns, which may be circumferentially disposed in a generally circular pattern. In other embodiments, there is only one column which contains a plurality of growth sites. In such an embodiment, the single column defines its internal space by, for example, coiling around the longitudinal axis.
In accordance with some embodiments, two or more of the growth sites are approximately equidistant from the longitudinal axis. In other embodiments, at least two growth sites are located on each of the one or more columns and at least some of the growth sites on each column are vertically spaced apart. In such an embodiment, the growth sites at generally the same vertical level may be approximately equidistant from the longitudinal axis. In still other embodiments, the growth unit comprises at least two columns and at least two growth sites are located on each column. In such an embodiment, the growth sites on each column may be vertically spaced apart, and growth sites at generally the same vertical level may be approximately equidistant from the longitudinal axis.
The nutrient supply module may act as a base into which the columns are located, and may be shaped to facilitate balance of the system, such as disc shaped. The columns may be shaped to facilitate the nutrient flow from the upper portion of each of the columns to the lower portion of each of the columns, such as tubular columns.
The plant growth unit may further include one or more fluid connectors, such as tubes, which connect the nutrient supply module with the upper portion of each of the one or more columns. The fluid connectors may be designed to facilitate the liquid nutrient flow from the nutrient supply module to the tops of each of the one or more columns.
Where each column supports a plurality of growth sites, the growth sites may be longitudinally aligned.
In yet another aspect of the present invention, there is provided a plant growth unit comprising one or more supporters, a plurality of growth sites supported by the supporters and means for establishing a liquid nutrient flow. The supporters may be radially disposable about a central vertical longitudinal axis defining an internal space between the one or more supporters. The supporters may be operable to form a generally closed perimeter around the internal space, each of the supporters having an upper portion and a lower portion. The internal space may be adapted to accommodate a light source. The growth sites may be radially disposed about the longitudinal axis and generally facing the internal space when the one or more supporters are radially disposed about the longitudinal axis and forming the generally closed perimeter. The liquid nutrient flow may be established by circulating the liquid nutrient to the upper portion of each of the one or more supporters and past the growth sites to the respective lower portion of each of the one or more supporters, so that the liquid nutrient flow comes into contact with each of the growth sites.
In some embodiments two or more of the growth sites are approximately equidistant from the longitudinal axis. In other embodiments, at least of the two growth sites may supported by each supporter and any growth sites at generally the same vertical level are approximately equidistant from the longitudinal axis. A plant growth unit may include at least two supporters supporting at least two growth sites, with any growth sites at generally the same vertical level being approximately equidistant from the longitudinal axis.
In some embodiments, the supporters include a first half and a second half which together form a generally circular perimeter around the internal space. The first half and the second half may each support a plurality of growth sites, with at least some of the growth sites on each of the first half and the second half being horizontally spaced apart from each other and with at least some of the growth sites on each of the first half and the second half being vertically spaced apart from each other. Any growth sites at generally the same vertical level may be approximately equidistant from the longitudinal axis. The plurality of growth sites on each of the first half and second half may form a plurality of generally horizontal rows, each of the horizontal rows having a plurality of growth sites.
Each of the one or more supporters may include a hollow wall having an inner side facing towards the internal space and an outer side facing away from the internal space. The inner and outer sides may define a hollow therebetween through which the liquid nutrient may pass. The growth sites may be supported by the inner surface so that roots of a plant located in one of the growth sites protrudes into the hollow. Each of the hollow walls may have a bottom on the lower portion so that the hollow wall is able to contain the liquid nutrient from which the liquid nutrient flow is established. In such an embodiment, the liquid nutrient flow establishing means may include one or more fluid connections, through which the liquid nutrient may pass, connecting the lower portion of each of the hollow walls to the respective upper portion of each of the hollow walls for establishing liquid nutrient flow. Such an embodiment may further include a tube extending along a horizontal length of the upper portion in the hollow of each of the hollow walls, each tube being connected to each of the respective one or more fluid connections, and one or more sprayers connected to each tube for misting roots extending into the hollow of each of the hollow walls.
In yet other embodiments, each of the one or more supporters may include a wall through which the growth sites are supported, so that roots of a plant located in one of the growth sites protrudes from the wall away from the internal space. In such an embodiment, the plant growth unit may further include a nutrient supply module. The liquid establishing means may include one or more sprayers in fluid communication with the nutrient supply module, the one or more sprayers misting roots protruding from the wall, and one or more collecting devices adjacent to the lower portion of the one or more supporters. The collecting device may be operable to collect the liquid nutrient as it travels to the lower portion of the one or more supporters. The collecting device may also be in fluid communication with the nutrient supply module to allow for recirculation of the liquid nutrient flow.
In other embodiments, the one or more supporters may be adapted to allow one or more supporters from another similar plant growth unit to be stacked on top the plant growth unit. Two or more similar plant growth units may be stacked on top of one another.
In some embodiments having two or more supporters, the supporters are free standing and moveable towards and away from a closed position wherein the supporters form the generally closed perimeter around the internal space. Where there are more than one supporters, two or more supporters may hinged to each other allowing for movement towards and away from the closed position.
The plant growth unit may further comprise one or more nutrient supply modules in fluid communication with the respective one or more supporters. The one or more nutrient supply modules may act as a base into which the respective supporters are located.
In another aspect, the present invention provides methods for growing plants in a growth unit. Supporting means may be disposed radially about a central vertical longitudinal axis, thereby defining an internal space between the supporting means, the internal space being adapted to accommodate a light source, and the supporting means having an upper portion and a lower portion. A plurality of growth sites may be introduced supported by the supporting means, the growth sites being radially disposed about the longitudinal axis and generally facing towards the internal space. A plurality of plants may be located in the growth sites and a liquid nutrient flow may be established by circulating a liquid nutrient to the upper portion of the supporting means to the respective lower portion of the supporting means, bringing the liquid nutrient into contact with the roots of the plants.